.S7A' WILLIAM SIEMENS, F.R.S. 113 



n-f erred to? Yet were mechanical science at these Conferences 

 to be limited to the objects exhibited in the South Gallery (and 

 separated unfortunately from apparatus representing physical 

 science by lengthy corridors filled with objects of natural history), 

 we should hardly find material worthy to occupy the time set apart 

 for us. But, thanks to the progress of opinion in recent days, 

 the barrier between pure and applied science may be considered 

 as having no longer any existence in fact. We see around us 

 practitioners, to whom seats of honour in the great academies and 

 associations for the advancement of pure science are not withheld, 

 and men who, having commenced with the cultivation of pure 

 science, think it no longer a degradation to follow up its applica- 

 tion to useful ends. 



The geographical separation between applied science and phy- 

 sical science just referred to, must therefore be regarded only as 

 accidental, and the subjects to be discussed in our section comprise 

 a large proportion of the objects to be found within the rooms 

 assigned more particularly to physics and chemistry. Thus all 

 measuring instruments, geometric and kinematic apparatus, have 

 been specially included within our range, and other objects, such 

 as telegraphic instruments, belong naturally to our domain. 



With these accessions, mechanical science represents a vast 

 field for discussion at these conferences, a field so vast indeed that 

 it would have been impossible to discuss separately the merits of 

 even the more remarkable of the exhibits belonging to it. It was 

 necessary to combine exhibits of similar nature into subdivisions, 

 and the committee have asked gentlemen eminently acquainted 

 with these branches to address you upon them in a comprehensive 

 manner. 



Thus they have secured the co-operation of Mr. Barnaby, the 

 Director of Construction of the Navy, to address you on the 

 subject of naval architecture, and of Mr. Fronde to enlarge upon 

 the subject of fluid resistance, upon which he has such an un- 

 doubted right to speak authoritatively. Mr. Thomas Stevenson, 

 the Engineer of the Northern Lighthouses, will describe the 

 modern arrangements of Dioptric lights, which mark a great pro- 

 gress in the art of lighting up our coasts. Mr. Bramwell has 

 undertaken the important task of addressing you on the subject of 

 prime movers, and Prof. Kennedy upon the kinematic apparatus 



VOL. III. I 



